1. Field of the Invention
The present invention relates to a device for providing an earth connection in a metal core printed circuit board and an improved high heat radiation efficiency. In particular, this invention relates to a device for providing an earth connection in a metal core printed circuit board in which a metal core of the printed circuit board is grounded by connection to a conductive shield casing having the metal core printed circuit board incorporated therein, by means of an electrical conductor which, preferably, has elasticity.
2. Description of the Related Art
As the density at which various electronic components are mounted on a printed circuit board increases, the amount of heat radiation therefrom also increases. To solve the problem of increased heat radiation, thus resulting in an increase of the temperature of the electronic components, a printed circuit board having a metal core, which has a high heat radiation efficiency, has been proposed (see e.g., U.S. Pat. No. 4,336,100.) The heat from the electronic components is uniformly distributed and radiated by the metal core.
This kind of metal core printed circuit board, referred to as a metal core PCB hereinafter, can be implemented, for example, in a bipolar signal/unipolar signal transducer module (B/U transducer) having high frequency devices operating at frequencies higher than 100 megahertz.
It is very important for the metal core PCB to be properly grounded, to ensure that the desired electrical characteristics are realized effectively and reliably.
An example of an earth connection of the metal core PCB is disclosed in, for example, Japanese Unexamined Patent Publication (Kokai) No. 57-155799, in which the metal core has an extension which can be directly connected to a frame which, in turn, can be grounded. In this known earth connection construction, however, the earth connection for the earth pattern of the metal core PCB must be established separately from the earth connection for the metal core. Also, the extension of the metal core, which is inserted in a groove formed in a fastening device provided on the frame to establish an electrical connection between the metal core and the grounded frame, may be accidentally bent and thus incorrectly inserted. The result is that a proper connection cannot be established between the core and the frame.